Introduction to robotics

1. INTRODUCTION

Robotics has applied technical science that combines machine and computer science. It includes a variety of fields such as machine design, management and control theory, microelectronics, computer programming, artificial intelligence, human factor and the theory of production. In other words, robotics is an interdisciplinary science that covers the areas of mechanics, electronics, information technology and automation. It primarily deals with the study of machines that can replace a man in the execution of tasks, such as various forms of physical activity and decision-making (decisions).

The development of robotics has been initiated the desire of man to try to find a replacement for himself that would have the possibility of imitation of its properties in different application, taking into account the interaction with the environment that surrounds it.

In the 20th first century, the road meets the name robot: introduced by the Czech writer K.Čapek 1920th Mr. in his play “RUR” (Rossum Universal Robots). Modern robots were created in the 1950s in the U.S. and come from the invention teleoptera, on the one hand, and numerical controlled machine tools, on the other side. In America, the Robot Institute of America, 1980, defined as višefunkcionalnog robot manipulators with the ability reprogramisanja, designed to carry materials, parts, tools and special devices through various programmed movements for the purpose of performing various tasks. This definition is rather restrictive, since it excludes mobile robot, which at the present time are experiencing expansion.

The general definition would be that the robot machine that has an intelligent connection between perception and action. In this context can be defined notion of intelligent robot as a machine capable of collecting information from the surrounding world and using knowledge about the environment is able to successfully move into it.

Computer Management application seeks robotic systems expert systems and artificial intelligence in the field of automatic control.

The main trend in robotics is related to mobility, intelligence and autonomy in nestrukturiranoj environment. This trend can be achieved using small, inexpensive and visokoperformansnih computer. The term robot, in this context, a system that is able to achieve planned behavior in the real world. Robotic systems receive signals (inputs) from the surrounding environment through sensors and act the same with plants (actuators).

The connection between the perception (sensing Eng.) and action (Eng. actuation) can be achieved simply signal or may include complex processes of decision making, interpretation and other aspects of the target reasoning. Most autonomous systems showed some forms of mobility: on land, under water, in air or in space.

Mobility can make use of wheels, legs, fins, rotor or other plants. The focus is on the possibilities of movement and self-sufficiency, not the fact that the imitation of biological systems. Of course, biological models of robotic systems are of interest as important as living systems prototypes of autonomous behavior. The subject of the study below is called. Industrial robotics including robot design, management and implementation in the industry.

1.1 INDUSTRIAL ROBOT

The most common is the notion of an industrial robot includes a robot that is also called robotic manipulator (Eng. robotic manipulator) or robotic arm (Eng. robotic arm). There are many different definitions of a robot, depending on the place and manner of implementation. The industrial robot has a satisfactory flexibility and versatility.

The main components of industrial robots are:

The mechanical structure or manipulator consists of a series of rigid segments (Eng. links) connected by joints (joints Eng.). Behavior is defined manipulator arm (arm Eng.), which provides mobility, wrist (wrist Eng.), which gives the versatility and top manipulators (Eng. end effector) that performs operations that require the robot.

Actuators (drive) is set manipulator moving in a certain movement of joints. Most frequently used electric and hydraulic motors, pneumatic and sometimes.

Sensors detect the status of manipulators (proprioceptivni sensors) and, if necessary, the status of the environment (heteroceptivni sensors).

Management system (computer) allows control and monitoring of movement manipulators.

Due to the properties of materials handling, manipulation and measurement, industrial robots have a successful application in the production process.

In the production process each object (material) can be transferred from one factory to another place for storage, further processing, and montisanja pakisanja. During the transfer, the physical characteristics of the facility are not subject to any changes. The ability of robots to pick up an object, transfer it into space by pre-defined path and away, makes it an ideal candidate for handling materials.

Typical application of this type are:

  • paletiranje (placing objects on the pallet in a specific order)
  • loading and unloading of storage
  • gride
  • sorting parts
  • packaging

The production process consists of transforming the building from raw materials to final product, during which the physical properties change as a result of machining or changing appearance due to the installation. The ability of robots to manipulate objects (processed) and tools makes it suitable in the processes of production.

Typical application are:

  • arc and spot welding
  • spray paint
  • turning and drilling
  • sticking and baking
  • laser cutting and water jet cutting
  • grinding and peeling
  • installation of mechanical and electrical group
  • installation of electrical panel
  • wring screws
  • wiring.

In addition to handling and manipulating materials in the production process is necessary to make measurements to test the quality of products. The ability of robots to explore space and the availability of three-dimensional measurement status allows the use of robot manipulators as measurement device. Applications of this type are:

  • monitoring (inspection) facility
  • contour finding
  • Detection of production shortfalls.

1.2 MATERIALS AND BASIC STRUCTURE OF ROBOT Manipulators

Robotic manipulator is composed of bodies (Eng. body), arms (Eng. arm) and wrist (wrist Eng.).The manufacturing processes commonly used robots attached to the substrate. At the end of the hand wrist is made up of many components that provide guidance to him in different positions. The relative movement between the different components of the body, hands and wrist are achieved by using a series of joints.

In industrial robots used in two basic types of joints: rotary (Eng. revolute joint) and auto (Eng. prismatic joint). Rotary joint about the axis of rotation, and auto (linear) linear movement of the axis. Two adjacent joints are connected by rigid segments. At the wrist attached to the hand (hand Eng.), which in technical jargon is called top manipulators (Eng. end of effector), tools (Eng. tool) and tongs (Eng. gripper). Top manipulators is not considered part of the robot, but is used to perform certain tasks required of a robot.

Some of the types of joints are shown in Fig. 1.1.

Figure 1.1. Some types of joint robotic manipulators.

For each robot is characteristic of the axis of the rotary or auto-move its segments. How to move a robot carried out in three-dimensional space, the first three axes are usually used to determine the position of your wrist, while the remaining axis orientation is determined by the top manipulators. General manipulator has six axes and can lead top manipulators in any position and orientation within the workspace. Robot workspace is a set of points in three-dimensional space that can reach the top of manipulators. The shape and volume of work depend on the structure of space manipulators, as well as the present limitations of mechanical joints.

It is now up to meet the following four basic structures of manipulators:

  1. rectangular (Eng. Cartesian or rectangular), or TTT,
  2. cylindrical (Eng. cylindrical) or RTT,
  3. spherical (Eng. Spherical) or RRT,
  4. rotary (Eng. articulated) or RRR.

The rectangular configuration of a robot has three auto joint whose axis of each eye (OG 1.2).Given the simple geometry, each level of mobility is corresponding with the degree of freedom in Cartesianovom space, since it is a rectilinear motion. The structure shows good mechanical strength. Accuracy pozicionisanja wrist is constant throughout the workspace.

In contrast to the high accuracy, the structure has low mobility, since all Joints auto. The working space of the robot’s prism. Cartesianov manipulator access facility on the side. ” If you want to access the building from the top down, the manipulator should be implemented as a stand (born Gantry manipulator). Cartesian structure allows the achievement of the working space and the manipulation of large bulky items. Therefore, the most commonly applied in the handling of materials and installation. Motors to launch joint manipulators are electric, pneumatic and rarely.

If the first joint of the rectangular structure of the rotary joint replacement, then the robot gets a cylindrical configuration, shown in Fig. 1.3. The working space of such robots is the volume between two vertical concentric cylindrical sheath (due to limited movement translatornog).Cylindrical manipulator shows good mechanical strength, but the accuracy pozicionisanja wrist decreases with increasing horizontal stroke. Mainly used for the transmission facilities of larger size and use hydraulic motors to drive the joints more than electricity.

j

Replacing the second joint cylindrical rotary joint robot configuration is obtained spherical robot configuration (OG 1.4). If there is a limit translating motion, then the workspace of the robot type of volume between two concentric spheres, with the restriction of movement, work space is part of the volume between two concentric spheres.

Mechanical strength is smaller than previous structures due to complex geometric and mechanical construction. Positioning accuracy decreases with increasing radial walk.Spherical manipulator is mainly used in mechanical engineering industry. Commonly used electric motors to run joint manipulators.

Robot types of SCAR (disambiguation Selective Compliance Assembly Robot Arm) also has two rotary joints and one auto, as shown in Fig. 1.5. This type of robots, all three axis vertical.SCAR manipulator karekterizira high strength for the loads on the vertical axis and deference to the load in the horizontal axis. Therefore, the SCAR is used for tasks montisanja vertical axis.Pozicionisanja accuracy decreases with increasing distance between the wrist and the first joint axis.

If you have used all three rotary joint structure receives the rotary manipulators, which is also called laktasta, anthropomorphic or articulated (OG 1.6). Axis of rotation of the second and third joints are parallel and perpendicular to the axis of rotation of the first joint. If there are no restrictions on rotational motion, then the workspace of the robot ball, and with the restrictions it put part of a complex shape, whose cross-section with the most in the crescent. Because of similarities to the human hand, the other joint is called a door hinge, and the third because the elbow joint connects the upper part of the hand with the forearm. To drive joint anthropomorphic structures used electric motors. Scope is very broad.

The above structure manipulators are obtained based on the application of wrist position and orientation of the top of the manipulators. If you want to achieve proper orientation in three-dimensional space, wrist must have at least three levels of mobility achieved rotary joints. Since the wrist makes the end part of the manipulators can be pressed on (compact), which would have resulted in complicated mechanical performance. Without going into details of construction, the realization of your wrist with the highest okretljivošću it is where all three axis rotary joint intersection at one point. This joint is called spherical. The main feature is the separation of the spherical joint positions and orientations of the top of the manipulators, hand is responsible for tasks pozicionisanjagornje cut-off point, while the wrist in charge of determining the orientation of the top of the manipulators. Joint implementation, which are not spherical

with simple mechanical point of view, but the position and orientation united and complicated coordination between the movement of arms and carrying out the task of the wrist.

Top manipulators is determined in accordance with the task to be executed by the robot. For material handling, top manipulators is made in the form of grab a form and dimensions depend on the object to be captured. For tasks mount, top manipulators is a tool (weapon) or certain devices, such as. welder, milling machine, drilling machine, a device for twisting screw.

Selection of robot application is conditioned by limited shape and size of working space, the maximum load, and dynamic accuracy pozitioning perfomance manipulators.

1.3 DIVISION ROBOT

Robots are essentially different due to their size, materials that can handle, which drives motor segments (zblobove), the type of applied sensor systems, and computer systems serve them. The general division of manipulators can be made in relation to the type of facility, the geometry of the working space and ways of managing mobility.

1.3.1 Types of plants

Moving body, hands and wrist robotic manipulators is enabled using the propulsion system (mechanism) robot. Transmission system determines the speed of hand movements, strength and dynamic performance of manipulators. In stanovitoj extent, operating system determines the area of application of robotic manipulators.

The most commonly used as one of the three following departments:

  1. Electric motor
  2. Hydraulic motor
  3. Pneumatic motor.

For most robotic manipulators today are using electric motors and DC often, and the alternate stepping, because they are relatively cheap, take up little space, with great speed and accuracy and the possible application of these complex control algorithms. However, the specific application (eg handling Incandescent steel or assembling parts of a car), when it requires manipulation of large loads, often used with hydraulics engine robots.

Hydraulic motor but high speed (greater than the electric motor) and strength, provides a peaceful maintenance positions due pressure oil. It is used by robots larger dimensions. The main disadvantages of these motors are their high cost and environmental pollution due to noise and the potential expiration of the oil. Pneumatic motors are applied in small robots. The advantage of their relatively low cost, high speed and not contaminate environment, and are therefore suitable for laboratory work.  Such engines are suitable for working with large loads, because it is impossible for stlačivosti ray still maintain the position. In addition to the presence of noise and the need for additional filtering and drying air due to unwanted dust and moisture. If it requires only the opening and closing of the grab (top manipulators), then in the final mechanism used pneumatic engine to squeeze rough brittle damage would not be the case.

1.3.2 Geometry Workspace

Division of manipulators due to the geometry of the workspace is:

  1. rectangular (Eng. Cartesian or rectangular), or TTT,
  2. cylindrical (Eng. cylindrical) or RTT,
  3. spherical (Eng. Spherical) or RRT,
  4. rotary (Eng. articulated) or RRR.

These manipulators are described in detail in Chapter 1.2.

1.3.3 Ways to control the movement of

There are two basic ways of moving the top of the manipulators:

  1. from point to point (Eng. Point-to-point motion),
  2. continuously move in the path (Eng. Continuous path).

In moving from point to point of top mobile manipulators by discrete points in the workspace and when it does not matter the path between points, but accuracy is important pozicionisanja. This method of movement is used for discrete operations such as spot welding and lifting and lowering objects.

In the continuous movement of the top path manipulators must move forward in a particular path in three-dimensional space and thereby are important pozicionisanja trajectory and accuracy.

Robots in which the trajectory of motion control can be used for dyeing, seam welding or sticking.

In addition to plant species, spaces and geometry of the working methods of managing the movement of a variety of additional features of a robot: the number of axes, the maximum weight of cargo, speed, reach, walk, navigation tools, repeatability, precision, accuracy and working environment.

1.4 DATA ROBOT

In the previous podpoglavlju listed some of the important characteristics of spam, such as the types of facilities, workspace geometry and method of managing mobility. Apart from these, the following are important characteristics of spam: the number of axes, the maximum weight of cargo, speed, reach, walk, navigation tools, repeatability, precision, accuracy and working environs.

1.4.1 Number of the axis (Eng. Number of Axes)

For each robot is characteristic of the axis of the rotary or auto-move its segments. How to move a robot carried out in three-dimensional space, the first three axes are usually used to determine the position of your wrist, while the remaining axis orientation is determined by the top manipulators. General manipulator has six axes and can lead top manipulators in any position and orientation within the workspace. We are a mechanism for opening and closing fingers is not considered an independent axis because it does not affect neither the position nor the orientation of the grab.

If the manipulator has more than six-axis, then the redudantne axis can be used to avoid obstacles within the workspace.

1.4.2 Maximum weight of cargo (Eng. Load-Carrying Capacity)

Maximum weight of cargo that a robot can be transmitted depends on the size, configuration and construction of robots, and on the drive system that drives a robot joints. Mass load could be a few pounds to several tons.

Maximum weight of cargo should be determined by the requirement that the robot arm is in its weak position. The case of polar or cylindrical configuration, this means that the robot arm up stretched out still.

1.4.3 speed (Eng. Speed of Motion)

Robot speed is very dependent on the type of robot and its application, and ranges in the area of 10 cm / s to 10 m / s. Maximum speed achieved by a robot whose arm extended to the maximum distance from the vertical axis robot. Hydraulic motor powered robots are faster than electric powered robot engine.

Speed, of course, determines how fast the robot can be made the default operating cycle.During the duty cycle is defined as the time required to perform similar movements periodičkog simple operation of raising and lowering objects. Then with the known length of the path can calculate the average speed manipulators. In manufacturing it is desirable to minimize the duration of the given task. Almost all robots have a mechanism with which you can adjust the speed. Determining the most desirable speed, to reduce production cycle time depends on several factors, such as:

a) The accuracy with which the top manipulators must position b) weight object that manipulates

c) The distance to which the transfer facility

Robot speed and accuracy are generally the reverse relationship.  If the accuracy requirement increases, the robot has to further reduce errors in his joints to achieve the target position. Mass of the object that is passed also affects the speed. Heavier objects mean and higher moments of inertia of the robot for security conditions must operate on them slowly.

The influence of the distance to which the robot carries the object to the speed of movement is shown in Fig. 1.7.

Vrijeme/udaljenost

Figure 1.7. The influence of distance on speed of movement.

Due to the principle of action and reaction, the robot is capable of peak manipulators move long way in less time than a short sequence tract, which is equal to the sum of a long road. Shorter distances do not allow the robot to reach higher speeds.

1.4.4 spatial resolution (Eng. Spatial Resolution)

Spatial resolution is the smallest robot prirašaj movement in which a robot can divide its work volume. It depends on two factors: the resolution of robotic control systems and mechanical inaccuracies. These factors simply konceptualizirati in the case of a robot with a single degree of freedom.

The control resolution is determined by the position of a robot control system and its feedback within the system is measuring. It is the ability of regulators to divide the total area of movement of individual joints in individual growth. The possibility of joint distribution in growth areas depends on the storage capacity (bits) in the control memory. Growth is sometimes referred to as addressable points. The number of separate, identified population growth for each axis on with:

Number of population growth = 2n where n is the number of bits in the control memory.

Eg. robot with the ability to store 8 bits can be divided into discrete area in 256 positions. The control resolution can be defined as the total area of movement divided by the number of population growth. It is assumed that population growth can make all equal.

First example In the case of a robot with one degree of freedom, we assume that he has one sliding (Auto) joint with a total area of 1 m. It is assumed that the robot control memory has a capacity 12-bit storage. Management is necessary to determine the resolution of this axis of movement.

The total number of control population growth may be determined as follows: Number of population growth = 212 = 4096

Total area of 1 m is divided in 4096 increase. Each position will be separated from neighboring

for

1 m/4096 = 0.000244 m or 0244 mm. Thus, the control resolution is 0244 mm.

In the case of robots with many degrees of freedom necessary to have a management resolution for each joint motion. Total control resolution depends on the movement of your wrist, like the movement of arms and whole body robot. Determination of control resolution is much usložnjeno in the case of robot that contains in its structure and auto-and rotary joints.

Mechanical inaccuracy in the robotic joints and segments and measuring system in the feedback mode robot control system is another factor that influences the spatial resolution. Mechanical inaccuracies resulting from elastic odstepena in structural members, gap zubčanika, stretch coil of rope, istjecanje oil in the hydraulic drives, and other imperfections in the mechanical system. These inaccuracies are more pronounced with bigger robots for the fact that more errors occur in a robot with longer components (segments, joints). Imprecision can also be caused by the size of the cargo that is handled, speed of movement of the hand, conditions of maintenance robots, and other similar factors.

On the basis of this, we can say that the spatial resolution is actually managing the above resolution degraded mechanical imprecision. Spatial resolution can be improved increasing capacity of memory management.

1.4.5 Accuracy (Accuracy Eng.)

Accuracy is a measure of the ability to bring a robot catcher (top manipulators) in an arbitrary position of the working space, ie, the difference between the possible and preferred position (OG 1.8). Accuracy can also be defined by a spatial resolution as the default ability to achieve the target point depends on how closely a robot can be defined growth drivers for the movement of each joint.

Suppose that the top manipulators in point A and point B that is closest to the next position to which he can get. In Fig. 1-8. can clearly see the difference between accuracy and control resolution (precision), assuming that the mechanical imprecision equal to zero.

However, taking into account the mechanical imprecision leads to the question of the possibility of reaching the target position. In relation to the accuracy of a robot is defined as half the spatial resolution.

1.4.6 Repeatability (Eng. repeatability)

Repeatability is a measure of the ability to top top robot manipulators lead again in the same position. Accuracy and repeatability are two different aspects of the accuracy of robots. The first defines the robot’s ability to achieve the default target point, and the other the ability of re-joining the same point. The error that can occur at re-return to the same position often less than 1 mm, and it occurs due to gear backlash and flexibility segments.

1.4.7 grasp and stroke (Eng. Reach & stroke)

The size of working space robot can be roughly determined by the reach and walk away.

Horizontal reach the maximum distance you can reach the wrist, measured from the vertical axis around which the robot rotates, while the total horizontal travel distance of the vertical axis at which the wrist can move. The difference between the horizontal reach and walk the minimum distance wrist from the main vertical axis, and how the size is positive, then the retrieval is always greater than or equal to go.

Vertical reach the maximum distance a robot wrist of the robot base, a vertical like a stroke can be defined as the total vertical distance by which the wrist can move. At the same vertical motion robot is less than or equal to the vertical reach.

For the example shown in Fig. 1.9. can be seen that the horizontal reach of robot configurations polumjera cylindrical roller outer sheath of working space, a horizontal stroke is the difference polumjera outside and inside the cylinder. It also can be seen that the vertical reach of a cylindrical robot to be greater than its vertical stroke if, with restrictions on movement of the second axis, the wrist does not allow the flow of border workspace.

In rotational robots reach the same fly so often these robots have a full working space. At the same robot to be protected because of samoranjavanja rotary robot can be programmed to hit himself or collisions with objects in their work surroundings.

1.4.8 Location of tools (top manipulators) (Eng. Orientation Tool)

Workspace shape is determined by using the first three-axis robot, and the remaining axis orientation determined by the closing mechanism can take (if the three-axis, then the tool can have an arbitrary orientation in three-dimensional space).

To determine the orientation of the top of the manipulators (tools) needed to define the three rotations around different axes: the axis of the turn (Eng. Yaw), ponisanja (Eng. pitch) and roll (Eng. roll), as shown in Fig. 1.10.

In this picture one can see that the top of the manipulators attached to a moving coordinate system S = [x, y, z] which together with the top Giba manipulators. In this coordinate system axis z axis corresponds to the basic tools and focus of the wrist and the y-axis is parallel to an imaginary line that is obtained by opening and closing the fingers. The remaining os x determines the right orientation of the coordinate system S.

In the beginning, the moving coordinate system with the same fixed coordinate system

S = (x ‘, y’, z ‘)

that

at the end of the forearm. Now it takes a certain order to define the turn, sinking and rolling.

Turning the top of the rotation about the axis manipulators x ‘, followed by sinking a peak manipulators rotation about the axis y’ and finally rolling, that is. the top of the rotation about the axis of manipulators’. In that positive angles are defined as zakreti in the direction opposite the direction of movement clockwise.

The final orientation is determined by the top of the manipulators and the turn order, ponisanja and rolling.

If the axis orientation required for top manipulators intersection at one point, then the robot has a spherical (Eng. Spherical) wrist. usložnjeno significantly in the case of robot that contains in its structure and auto-and rotary joints.

Figure 1.10. Turn, the plunge and rolling the top of the manipulators

Mechanical inaccuracy in the robotic joints and segments and measuring system in the feedback mode robot control system are another factor that influences the spatial resolution. Mechanical inaccuracies resulting from elastic  in structural members, gap gear, stretch coil of rope, leakage oil in the hydraulic drives, and other imperfections in the mechanical system. These inaccuracies are more pronounced with bigger robots for the fact that more errors occur in a robot with longer components (segments, joints).  Imprecision can also be caused by the size of the cargo that is handled, speed of movement of the hand, conditions of maintenance robots, and other similar factors.

On the basis of this, we can say that the spatial resolution is actually managing the above resolution degraded mechanical imprecision. Spatial resolution can be improved by increasing the memory capacity management.

1.4.9 Working environment (Eng. Operating Environment)

Working around a robot depends on the task that he performs. Robots often work in hazardous or contaminated environment, for example. During the transport of radioactive material, then the painting, welding or working in smelters. Such robots submitted to very high temperatures and different pollution in the air. The other extreme type of work environment are very clean working environment, for example. In poluvodičkoj industry, which is very carefully monitored temperature and air humidity. In this case, and I am a robot must be very clean in order to minimize contamination of working materials to a minimum.

1.5 MODELING AND MANAGEMENT OF ROBOTICS manipulator

In all of the application of industrial robots perform a task implies a particular movement, which is attributed to the top of the manipulators. Motion can be smoothly, if there is no physical interaction between the end of the manipulators and the environment, or if there is such limited interaction. For the successful execution of the movement is in charge of the top manipulators drive (actuator) joint manipulators with commands that are in line with the desired trajectory of movement. Manage the movement of the top manipulators requires accurate analysis of the characteristics of mechanical structures, actuators and sensors. The aim of such analysis is to determine the components of mathematical models of industrial robots. Modeling of robotic manipulators is necessary to find the appropriate management strategy.

1.5.1 Modeling

Building a robot involves a mathematical model formulation of its components, ie. drive models (Engine) to manage the movement of joints, kinematics model segments (segment length and location of the axis of the joints) and inercijske models of mass, center of mass and moments of inertia and cargo segments. Parameters of these models need to be measured or estimirati application of different procedures. Design a robot restricted by understanding the environment in which the robot operates and the tasks that are set before him.

Manipulators kinematics analysis of the structure refers to the description of motion manipulators with respect to fixed coordinate system (Cartesian), not taking into account the forces and moments that have caused the movement. This distinction is important because of the kinematics and differential kinematics. Kinematics describes the analytical relationship between the ankle and the position and orientation of the top manipulators. Differential kinematics describes the analytical relationship between the movement of joints and movement expressed through speed manipulators.

There are two key problems for the formulation of kinematičkih link in robotics:

  1. direct kinematics problem
  2. inverse kinematics problem.

General procedure that describes the movement of the top of the manipulators as a function of motion of joints is based on the theory of linear algebra. Inverse solution of the problem is of crucial importance for the transformation of the desired motion from the top of the manipulators workspace in the corresponding movement in the joint space. Availability cinematic manipulators model is useful for determining the relationship between force and torsion

(turning torque) applied to the joints and the forces and moments applied to the top of the manipulators static equilibrium configurations. Kinematics manipulators is the basis for a dynamic equation, ie. equation of motion manipulators as a function of forces and moments acting on the manipulator. The availability of a dynamic model is useful for designing mahaničko structure, choice of actuators, the determination of management strategies and computer simulation of motion manipulators.

1.5.2 Management

Based on the assigned task manipulator follows that you refer to the movement of joints or directly to the top of manipulators. In the case of handling the materials you need to top manipulators follow the desired path (trajectory). Trajectory planning is the basis for process control manipulator.

Management problem consists of determining the forces and moments on the joints narinutih manipulators that provide the desired movement (pre-determined) path. This issue is very complex, since manipulator system is connected with that movement of one segment affects the movement of other segments. If the task requires interaction between the top manipulators and environmental management problem is much complicated as it should be taken into account the power of touch place (force touch, eng. Contact forces). In order to perform the requested move is necessary to use actuators and sensors. Generalized block-scheme of industrial robots on the Fig. 1.11. Control device (computer) act on the plants (engines) that trigger mechanism robot to the top manipulators (strikes, tongs, tool) came to the site in relation to the building or the surrounding area. By measuring the position and velocity of the top of the manipulators (the system for measuring position), through internal feedback we get information we can correct the movement. Dot is shown to be via external feedback can get information from the environment (sensors), a system for recognizing when combined with powerful computer provides a much higher level of information (AI).

Industrial robots can be divided into four groups as a way of management:

  1. Sequence constrained robots
  2. Robots with management from point to point
  3. Robots with continuously controlled by the path
  4. Intelligent Robots

Of the four categories, robots are limited to sequence the lowest level of management, as opposed to intelligent robots that possess the most sophisticated features.

The first group of robots is used for servo control to indicate the relative position of the joints.Instead, they are setting upravljajni limit switches and / or mechanical lock to reach the target point path for each joint. The establishment of the position and sequence of these blocks comprises a mechanical adjustment manipulators. With this method of management, individual joints can be pomjerati to the extreme path. This has the effect of severely restricted the number of clear points that can be specified in a program for this robot. The sequence in which the cycle of movement takes place is determined by the stepping switch or other device with the possibility of selection. This device is an integral part of the robotic controller and the signals from each individual plant to successfully carry out tasks set him. In general there is no feedback associated with limited sequence robot in order to indications of achievement desired position. Any of the propulsion system (electric, hydraulic and pneumatic) can be used in this system of governance. However, most are in use pneumatic drives.  Robots of this type are applied to perform simple movements, such as raising and lowering operations.

In subheadings 1.3.3 lists the main characteristics of the second and third groups of robots. At some of next chapter will devote special attention to these robots.

Robots that have the properties of artificial intelligence called intelligent robots. Intelligent Robots constitute a class of industrial robots to exercise options other than possession of the programmed motion can and interact with the environment in a manner of expression of intelligent features. In addition, these robots can the performance of specific actions to change the program cycle in response to changing conditions in the workspace. One of the most important characteristics of intelligent robots is making decisions based on data obtained from sensors. While performing surgery intelligent robots can komunicisanja with a man or a computer system. Intelligent robots are programmed using the symbolic language, which differ from traditional computer programming languages.The application of intelligent robot arises from the use of high levels of language to perform complex and sophisticated activities. Typical tasks of the application assembly and arc welding operations.

In the end, imposing an ethical question regarding the application of robots in manufacturing contemporary:

– Will robots squeeze out people from work?

– It becomes like a self-introduction robotization purpose?

– They are like robots people or people robots?

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